1. Field of the Invention
The present invention relates to a vehicle body height control system, or more particularly, to a vehicle body height adjusting system with an improved travelling feeling or performance during the process of vehicle body height adjustment. The system of this invention is hereinafter referred to simply as the vehicle height control system.
The present invention is applicable to a vehicle height control system comprising a vehicle height adjuster for each of the wheels (a single vehicle height adjuster may be provided for all of the rear wheels) for controlling the distance between each wheel and the vehicle body, that is, the vehicle body height, with each adjuster operating independently.
2. Description of the Prior Art
A vehicle height control system has been proposed heretofore, in which the vehicle height is controlled at a target level by employing a plurality of vehicle height adjusters in order to attain a desired vehicle height in response to the number of passengers, the amount of loads, the travelling conditions and the road surface conditions on which the vehicle is travelling.
In such a conventional vehicle height control system, when all the vehicle height adjusters are extended or contracted by the same length, the extension or contraction rate (the adjusting rate) would be different between the respective vehicle height adjusters due to the differences in the loads on or in the suspension spring characteristics of the respective vehicle height adjusters.
This variation in the adjusting rate causes an unstable slant of the vehicle body under adjustment and undesirably makes the driver and passengers (hereinafter simply called "the driver") feel uneasy.
This problem is attributable to the fact that each of the vehicle height adjusters is extended or contracted regardless of the adjusting rates of the other vehicle height adjusters.
The present invention is intended to obviate the above-mentioned disadvantage of the prior art system.